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    Sbc 350 knocking issue

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    HeavyChevy77
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    Sbc 350 knocking issue

    Post  HeavyChevy77 on Thu Feb 08, 2018 5:34 pm

    Ive been chasing my tail on this knocking noise
    Started as a light tick that grew louder
    Sound like its coming from torque converter/pump area
    Can hear a solid click knock between the two.
    When I start in the morning its ticks and goes away a little at higher rpms may go away when driving but stick it in park tick tick tick
    But I noticed sometimes it would stop when the car rolled back until it sat on the locking pin then it stopped
    Wierdly I would hear it as it warmed up it may or may not go away. Another weird think it would tick in park neutral I stick it I. Gear and it stops then starts again after a few seconds then picks up speed and keeps with the rpm.
    Yesterday tired to find a loose anything maybe hitting the fame or something
    Found the metal trans lines were tapping the exhaust fixed it but was not the issue
    I have already pulled the inspection plate and checked the flexplate bolts and torque converter bolts
    Front of trans pump had oil seepage (worn out th200/still shifts great despite having broken clutch fibers)
    Started after tinkering and still was present let it warm up and then gave up .
    Started today in the morning and after 10 seconds shit was knocking loudly like something was. Hitting metal so shit her off and said some choice words.
    Looking to yank the trans to remove and thoroughly inspect flexplate and have the old engine to take stuff off if needed
    Also would it be ok to start the engine in the engine bay with transmission removed/decoupled
    Please any advice
    First plan of attack
    Pull cover
    Inspect bolts
    Remove trans
    Inspect trans and flexplate looking for shiny metal from rubbing/ hitting
    *ok?* start engine with teans disconnected to isolate noise
    I heard can be
    Cracked/broken flexplate
    Rod/wrist pin
    Broken crank
    Crank hitting pan (I have aftermarket chrome pan on/never made noise when installed and ran previously)
    Loose torque converter bolts/flexplate
    Please help with this crate 350 before it grenades
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    Kit1078
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    Re: Sbc 350 knocking issue

    Post  Kit1078 on Thu Feb 08, 2018 10:35 pm

    Do you have an oil pressure gauge? If so, what does it read at idle? If not, does the oil light come on at an idle?

    Also, check the oil, see if there are any flecks of metal in it. if there is no metal on the dipstick, you might also want to pull the drain plug on the pan, just to make sure.

    I had a cheap chrome oil pan once, and didn't have any clearance issues.

    You should be able to unbolt the torque converter and slide it back into the transmission about an inch or so, then try starting the car. That should isolate the motor from the transmission so you can tell if the noise is coming from the engine or not. If you're still having the noise after you unbolt the torque converter/remove the transmission, and if you don't have any metal flakes in the oil, I'd try adjusting the valves. A loose rocker arm can make a hell of a racket.
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    HeavyChevy77
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    Re: Sbc 350 knocking issue

    Post  HeavyChevy77 on Fri Feb 09, 2018 1:14 am

    No pressure gauge just a dummy light
    Does no illuminate while running only key on engine off
    Thanks for the advice I will unbolt the converter and slide it back but ima double check the eng to trans bolt first though
    No metal in oil but ima gonna change the oil anyway
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    HeavyChevy77
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    Re: Sbc 350 knocking issue

    Post  HeavyChevy77 on Sun Feb 11, 2018 9:08 pm

    Today had time to creep under and see whats up
    Found a broken flexplate, cracked all-around the bolts and seperated into two pieces, also a leaky transmission.
    Looking to get a summit flexplate and th350 to replace the old tired leaky th200. From what I read its a direct replacement other than using a lockdown cable than a tv and a vac line to modulator is there anything else like different trans lines or something. Thanks for the direction guys.

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